Ethers are manufactured in many processes either directly or as side products to the production of other oxygenates. Examples include isopropyl ether (IPE) from the production of isopropyl alcohol (IPA), secondary butyl ether (SBE) from the production of methyl ethyl ketone (MEK), methyl tertiary butyl ether (MTBE) from MTBE production units or isobutylene purification, tertiary amyl ether (TAME) from amylene production, C8 to C30 ethers from the production of oxo alcohols as well as many others.
Currently, many of the small ethers having C4 to C10 carbon chain length are blended into motor gasoline (Mogas) for oxygenate content. Legislation is progressing that may prevent this disposition from being available. This necessitates finding alternate dispositions for these ethers.
U.S. Pat. No. 4,254,296 discloses a process for the preparation of tertiary olefins starting from the corresponding alkyl tert-alkyl ethers, characterized in that the tert-alkyl ethers are reacted in the presence of a catalyst selected from the group consisting of a crystalline silica having a high specific surface area corresponding to the general formula 0-1MnOm·1SiO2, wherein MnOm is the oxide of a metallic cation capable of entering into the silica lattice as a substituent for silicon or as a salt of polysilicic acids and/or an aluminum-modified silica corresponding to the general formula as follows: 0.0006-0.0025 Al2O3·1SiO2.
U.S. Pat. No. 4,395,580 discloses a process for producing a tertiary olefin of the formula: R2CH═CR1R3 by decomposition of the corresponding tertiary ether of the formula: R2CH2C(R1)(R3)—O—CH2R wherein R1 and R3 are each independently an alkyl, arylalkyl, aryl or alkylaryl radical; and R2 and R are each independently a hydrogen atom or an alkyl, arylalkyl, aryl or alkylaryl radical, said process comprising the step of contacting said ether, in the presence of steam, the molar ratio H2O tertiary ether being from 2 to 8, with a catalyst consisting essentially of alumina having deposited thereon at least one modifying agent, said agent being titanium, zirconium or hafnium, as the elemental metal or a metal compound, the content of said metal or metal compound, expressed as the elemental metal, being 0.01-5% by weight with respect to the alumina, said alumina, after incorporation of the metal or metal compound, having a specific surface of 80-300 m2/g; whereby the tertiary olefin is produced in high purity, and parasitic side-reactions which decrease the yields of tertiary olefin and of recovered alcohol are minimized.
U.S. Pat. No. 5,914,433 discloses a process for producing polymer grade olefins comprising a) passing an oxygenate feedstock comprising an alcohol or an ether having from 1 to 4 carbon atoms per molecule to a fluidized reaction zone containing an aluminophosphate molecular sieve catalyst in the presence of a diluent at conditions effective to convert the oxygenate feedstock to a light olefin product stream comprising ethylene, propylene, and butylene and to produce a spent aluminophosphate molecular sieve catalyst; b) passing the light olefin product stream to a separation zone to separate the light olefin product stream into an ethylene stream, a propylene stream, and a mixed butylene and heavier stream; c) withdrawing at least a portion of the spent aluminophosphate molecular sieve catalyst from the fluidized reaction zone and passing the spent aluminophosphate molecular sieve catalyst to a regenerator to regenerate the spent aluminophosphate molecular sieve catalyst with an oxygen-containing stream to produce a regenerated catalyst; and d) returning a first portion of the regenerated catalyst to the fluidized reaction zone and admixing a second portion of the regenerated catalyst with a portion of the mixed butylene and heavier stream to provide a feed admixture and passing the feed admixture to a cracking reaction zone at conditions effective to convert the mixed butylene and heavier stream to produce a second product stream comprising additional amounts of ethylene and propylene and to produce a third regenerated catalyst portion; and e) passing at least a portion of the second product stream to the fluidized reaction zone.
Additional references of interest include: U.S. Pat. Nos. 4,352,945; 5,171,920; 5,227,564; and EP 0 123 449 A1.